1. Technical Field
The present invention relates to technical fields of an electro-optical device such as a liquid crystal device, an electronic apparatus including the electro-optical device, and a transistor.
2. Related Art
In an electro-optical device, data lines and scan lines are provided in an image display region of a substrate so as to intersect each other, the pixel electrodes are provided on intersections between both lines in a matrix, and the switching of the pixel electrodes is controlled in each of the pixels. In each pixel, for example, a transistor having a Lightly Doped Drain (LDD) structure is provided as a pixel switching element for controlling the switching of each of the pixel electrodes. In the LDD structure, low-concentration impurities are injected into a semiconductor film of the transistor so as to form a low-concentration impurity region, and high-concentration impurities are injected so as to form a high-concentration impurity region. By electrolysis mitigation effect based on the mutual impurity concentration gradient of the low-concentration impurity region and the high-concentration impurity region, leak current (that is, off-leak current) upon non-operation of the transistor is reduced.
For example, JP-A-5-3209 discloses technology of forming a sidewall, injecting high-concentration impurities and forming a high-concentration impurity region after a low-concentration impurity region is formed in a semiconductor film. According to JP-A-5-3209, in order to reduce leak current of the transistor due to crystal defects of the low-concentration impurity region of the semiconductor film (silicon substrate), due to the existence of the sidewall, the sidewall is to be formed in a crescent shape or a concave shape.
However, according to JP-A-5-3209, a process of manufacturing the transistor may become troublesome by the processing of the sidewall. Accordingly, yield of the manufacturing process may deteriorate by such troublesome processing.